The circular cut-out (73 mm ø) in the baffle is for the BR 15.34 tube. The 78 mm cut-out in the rear panel is for mounting the ST 77 terminals. The crossover unit is mounted on the panel behind the bass cut-out.

The damping is a simple matter: as shown in the diagram, the four free square openings of the stiffening construction take one mat each, so that the upper part of the speaker cabinet is loosely filled. The lower part is left completely empty.